The invention relates to an infinitely variable traction roller transmission in which power is transmitted through traction rollers pivotally supported between toric input and output discs by a flexible support structure extending in the space between the discs and interconnecting the supports for the traction rollers.
In such transmissions, the traction rollers are mounted on support structures which, when pivoted, cause engagement of the traction rollers with the toric discs in circles of varying diameters depending on the desired transmission ratio. The pivotal traction roller support structures are so mounted that they can be moved axially for initiating a change in the transmission ratio. This is accomplished for example by flexible support sheets as shown in U.S. Pat. No. 4,086,820 which issued May 2, 1978 to Charles E. Kraus.
However, the forces applied to the traction rollers and through the traction roller support structure to the tension sheets are substantial and, consequently require support structure of great strength together with an adequate pivot bearing therefor. Also, the connections of the tension sheets to the traction roller support structure require special care in order to avoid problems after extended use of the transmission.